View file siwap.ru/AJAX/chat/checkNewMessages.php

<?php
require_once($_SERVER['DOCUMENT_ROOT'].'/system/App.php');
	
if ($sys->isAjax())
{
	/*
	if (empty($me['cache_file'])) Base::update('user', $me['id'], ['cache_file' => $core->hash(20).'.dat']);
	*/
	$cacheFile = ROOT.'/system/cache/chat/check-messages.dat';
	
	if (!file_exists($cacheFile)) file_put_contents($cacheFile, time(), LOCK_EX);
	
	$lastAjaxCall = isset($_GET['timestap']) ? (int) $_GET['timestap'] : 0;
	$lastChangeFile = filemtime($cacheFile);
	
	while ($lastChangeFile <= $lastAjaxCall) 
	{
		usleep(10000);
		
		clearstatcache();
		
		$lastChangeFile = filemtime($cacheFile);
	}
	
	$dataSourceFile = file_get_contents($cacheFile);
			
	$json = [
		'success' => 1, 
		'comment' => 'INFO: '.$dataSourceFile,
		'timestap' => $lastChangeFile,
	];
}
else
{
	$json = [
		'error' => 1, 
		'comment' => '404 Bad Request',
	];
}
echo json_encode($json, JSON_UNESCAPED_UNICODE);